This study analyses the age, breed, sex, body condition score, and diet of dogs and cats and estimated prevalences of the most common disorders of 31,484 dogs and 15,226 examined by private veterinarians in the United Sates during 1995. Lameness, disk disease, lipoma, and allergic dermatitis were the main complaints for dogs, whereas renal disease, cystitis, lower urinary disease and inappetence were the main complaints for cats. However, many conditions such as flea infestation, conjunctivitis, diarrhoea and vomiting were common to both species.